Posted:7th Jul 2006OK people. I'm not in for a fight but I had a thought today at work.

I've been reading a lot on Darwin and natural selection in my spare time and from a biology degree I wondered what people think.

Some of this is going to sound nasty or evil but believe me this is not my intent. My intent is more along the lines of an "IF" scenario.

Everybody has heard of natural selection. My thought ran along these lines:

With all the advances in medical technology and proceedures that are occuring, many of which are prolonging the life of people suffering from various genetic based conditions (NOT just abnormalities but also diseases linked to genes) to an age viable for reproduction. IS the human race's use of medicine possibly going to be it's own downfall?

I'm not saying my thought process was right, but this this the process it followed.

with man adapting his environment to himself instead of vise-versa is he "stepping out" of natural selection?

With the extension of life in those with genetic problems to a reproductive age, is man propegating the spread of genes that would have been cropped by the evolutionary chain.

the increase of medical disorders IS growing (probably due to the increase in population I'll admit) as is the population of the planet.

population growth is exponential whereas food growth IS Linear.

With the medical extension of life and the "stepping out" of natural selection will the spread of "poor genes" (sorry I did say this would sound harsh) come to haunt us OR will the human genome mainain a balance?

Will the advancement of medical science lead us to a world akin to the movie GATTACA in order to survive?

I sometimes think that nature has found it cannot evolve a large enough predator to curb the growth of human population (also we humans would probably hunt the poor bugger to death) so has it decided that smaller is better? Everyone knows (sorry for the analogy) that without the wolves (today it is a gun and the annual cull) the deer will perish due to exponential population growth and limited food sources.

Is DNA going to become the wolf of the Humans?

sorry i was a lot tidier in my head and when I have thought about it a bit more and seen some of your responses it may become clearer.

sometimes odd stuff does just pop in my vacuous head and I have to get it down before I get confused unfortunately I had half a day left at work

what do you think?

A couple of balls short of a full cascade... or maybe a few cards short of a deck... we'll see how this all fans out.

with man adapting his environment to himself instead of vise-versa is he "stepping out" of natural selection?

No. i don't think he's stepping out, i don't think that's possible. I think we like to think it's possible but on the other hand the evolution of super-bugs like MRSA proves that we are not over and above being part of nature.

So another question i would ask, is, since we are still a part of nature, is our use of medicine as a preventative cure for well... death... part of our evolution or is it a temporary fix that means as soon as the ultimate super bug evolves beyond the current capabilites of medicine (in the manner that MRSA evolved) will it help or detriment us?? Maybe we should have evolved our bodies against disease instead lazing back and relying on the drugs?

Posted:7th Jul 2006Jo, yes, they are here because we selected them. Superbugs aren't any different from the old bugs. Staphylococcus aureus is still the same bug, whether it's methicillin-resistant or not. The only thing that makes it "super" is that it's resistant to so many antibiotics. In general, a bug that was once sensitive to a given antibiotic can't become resistant to that antibiotic without being exposed to it.

It's a very simple experiment. Take a bacterium, say E. coli because we use it a lot in the lab, and suppose it's sensitive to ampicillin. Now, plate out the bacteria on a petri plate and before you put them in the incubator to grow, put a disk soaked in a given concentration of ampicillin in the middle. The next day you will see colonies all over the plate except in the middle of the plate where that disk was you'll see a halo around it where there will be no colonies of bacteria.

So you pick the colony closest to the disk and grow it overnight in liquid medium and then the next day, plate it out but this time use a disk with a higher concentration of ampicillin in the middle. Again, pick the closest colony to the disk and grow it in liquid medium overnight. Plate it out and put a disk soaked with an even higher concentration of ampicillin in the middle, and wash, rinse, repeat...

Keep this up for two weeks and you will eventually get colonies that can grow without any trouble on a pretty high concentration of ampicillin.

You can see how this situation is easily simulated in the human body. Someone goes home and takes two days of their scheduled ten of their antibiotics and they kill off MOST of the bacteria, but they leave the strongest behind. Go through enough cycles of this and you get resistant bugs.

And this is why some bugs, like vancomycin-resistant Enterococcus are so freakin' scary. They prove that indeed, if you build a better mousetrap, someone will come up with a better mouse.

it DOES seem that medicine is helping to evolve pathogens VERY quickly.

as bacteria is the only species we can "watch evolution happen" in. that suggests a rather rapid mutability of species.

I got the feeling when I thought of this that the end of man WON'T be an ELE (Extinction Level Event) i got the feeling man would kill himself slowly (and possibly painfully) with the use of medicine. Mans greatest achievement could be his down fall.

So what you are saying Doc is that medicine is In fact helping to Evolve stronger pathogens... ouch

A couple of balls short of a full cascade... or maybe a few cards short of a deck... we'll see how this all fans out.

What about the spread of (sorry again) poor/defective genes? even as much as a couple of hundred years ago people with genetic anomalies rarely reproduced or didn't survive to a reproductive age.

There is ONE thing that seems strange to me I was watching a programme on Dwarfism last night (after my original post) and I got the impression the gene for Dwarfism is in fact a dominant gene as they were talking about offspring of a pair of "dwarfs" (some preferred other terms) having only a "single dose" of the dwarfish gene, sugggesting the allele for dwarfism was heterozygous.

Is this a genetic randomness or is dwarfism spreading for a purpose?

A couple of balls short of a full cascade... or maybe a few cards short of a deck... we'll see how this all fans out.

Posted:8th Jul 2006What about the whole plastics leaching psuedo female hormones into their (food based) contents, and mens fertility dropping as a result. (Cos they're getting feminised by fake hormones in their food) One of some amount of reasons for low sperm counts and the increased need for IVF in otherwise 'normal' couples.

But that won't kill off all of humanity. All the developing countries still have normal and lots of births. Same with medicine. They hardly have any of it, so no danger of them killing themselves slowly with it.

I personally think that war due to resource (energy, water and food) shortage will kill us all a lot sooner. 2030 now for oil running out... yay! And water wars have almost broken out already, when the asian water table starts to dry up properly, then you'll see some fireworks, I'm sure.

"the now legendary" - Kaskade"the still legendary" - Kaskade

I spunked in my friend's aquarium and the fish ate it. I love all fish. Especially the pink ones. They are my bitches. - Anon.

Posted:8th Jul 2006The genes thing could hurt too tho, unless we stop wasting our time on crap stupid things, cos we're going to need more time to devote to medicine and caretaking and all this extra stuff that comes with people and treatable probelms. We're already not doing a good enough job. But at the moment its probably still only a drop in the proverbial bucket....

Posted:8th Jul 2006Through medical advances, we can stifle the effects of natural selection on human populations, but we can also enhance the effects of artificial selection on human populations.

For example, we can fix congenital malformations like cleft lips that would have made it harder for that person to compete for a mate. However, we can also diagnose those defects in the womb, and kill the child before it matures.

Last year, Brittan aborted 2,000 children with a risk of physical or mental handicaps:

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2006/07/05/nhealth05.xmlbr>Artificial selection can be just as brutal as natural selection. People with undesirable traits will be eliminated. I do not think that medical advances will really weaken humanity in the long run. A doctor may help a genetically inferior person prolong their life, but a doctor can also help that person cut short the life of any offspring that threatens to carry on the defects.

Posted:8th Jul 2006I don't think our proliferation over the planet or extended living will hurt us. Genes are awkward and we only know aboput the an eighth of the story at the moment. We still don't really understand how genes influence protein production or how they are selected. Or how proteins influence growth. When i say that i mean we have a rough idea but not to the septh that the genome project ad taken us on the genes. Though they are working on it. I feel it is hard to avoid natural selection especially while on this planet we are still subject to heavy competition mainly from eachother which will shape evolution. More of the same i think is what the future will se evolution wise.

The only reason we have noticed more genes for inheritied disease in recent years is that we have been looking for them. The more you look the more you see, eventually this will level out. And we can get down to treating all diseases. I think.

And as the skin rips off i cherish the revolting thought That even if i quit There's not a chance in hell i'd stop- The Dresden Dolls

Posted:8th Jul 2006Patriarch917 - you just pretty much said what I did.

well are propegating gene's we class as "defects" like cleft palates by "fixing" them and giving the genes a better chance of being passed on.

artificial selection is VERY MUCH the world described in the film GATTACA where your traits are decided from the range of genes available and your future role / job is decided on your genetic map.

I would prefer MCP's future to an extent. Wars ARE the BEST population control for humans, unfortunately with our current technology a full scale "world war" for resources would probably damage the very recources we would be fighting for, (Air and water contaminated and fuel deposits burnt or destroyed)

Although we don't understand the extent of protein production in genes due to the recent discovery that the introns AREN'T junk DNA left over from primordial evolution. we are aware that the person giving birth to an individual plays as much role as the DNA. Every mammal has VIRAL DNA as a part of its make up. and until recently it was thought to be DNA left over from a previous stage of evolution.

That was wrong without this STOLEN viral DNA from some long distant past no mammal could ever be born as they would be rejected by the mother.

Even if genes cannot be seen the disease that they are linked to were (in many cases) able to be "cured" prior to the completion of the genome project. so "finding" the gene's was only a matter of creating an early warning system.

Basically I can no longer see how man will continue to evolve. Any Morphalogical differences will be seen as "defects" to our view of the norm. the only way i can see us developing is by resistance to disease, and by way of what doc said we are "helping" diseases become more resistant.. helping disease to "evolve" which happens a lot quicker at a micro level than a macro level. And it's mans use of medicine which is creating the environmental pressure for these pathogens to overcome for survival.

Should a terminal disease like HIV / AIDS become airbourne (although doubtful) what would man do?

A couple of balls short of a full cascade... or maybe a few cards short of a deck... we'll see how this all fans out.

That was wrong without this STOLEN viral DNA from some long distant past no mammal could ever be born as they would be rejected by the mother.

It isn't really stolen, it's more parasitic. Now, I'm not familiar with viral DNA having anything to do with regulating the mother's immune system, it stands to reason that certain types of viral-derived genes could be involved in down-regulating the maternal immune response to the placenta.

The human genome is littered with remains of "dead" retroviruses very similar to HIV in many ways. Chances are that they ravaged a former population and those who were born with "dead" varieties already in the genome were intrinsically immune to infection. And now these "dead" viruses are parasites, eternal passengers.

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Should a terminal disease like HIV / AIDS become airbourne (although doubtful) what would man do?

Most of us would, at this point, probably be treated or die of it. It would select for self-motivated people who could take their medicines.

Diseases like Ebola and Bird Flu rarely kill too many people because if you kill your host too quickly you can't get passed on. That's why Ebola has never become a serious health threat. Of course, we're quite capable of having a vaccine, it's just that it's not worth it because (practically) it rarely becomes a problem and (cynically) it only affects dark-skinned poor people.

Posted:11th Jul 2006quite true Doc the viral DNA is also found in a type of parasitic wasp that lays it's eggs in Spiders, the DNA prevents the spiders immune system from rejecting the eggs, they hatch and eat the spider from the inside out.

*runs to army surplus for haz-mat suit and water purifier*

A couple of balls short of a full cascade... or maybe a few cards short of a deck... we'll see how this all fans out.

quite true Doc the viral DNA is also found in a type of parasitic wasp that lays it's eggs in Spiders, the DNA prevents the spiders immune system from rejecting the eggs, they hatch and eat the spider from the inside out.

*runs to army surplus for haz-mat suit and water purifier*

The example I know is that the wasp carries the virus in its oviducts and lays the eggs in a caterpillar. The virus downregulates the caterpillar immune system and prevents it from encapsulating the wasp larva. It also prevents progression of the caterpillar into pupation. The movie "ALIEN" was based on this idea. On maturation, the wasp larva becomes infected with the virus, which reproduces in its oviduct, and the cycle continues. Wasps of this species have been isolated without the virus and they are able to fertilize eggs and produce larvae, but they cannot reproduce because the larvae cannot survive in the host caterpillar.

Evolution comes up with rather strange solutions. Including one remarkable organism that dies 30% of the time in childbirth, devotes over 30% of its natural lifespan to the rearing of a single youngling, has few natural defenses or abilities, and yet has a disproportionately large brain and rather well-developed forepaws that enable it to become the dominant species on the planet.

Evolution comes up with rather strange solutions. Including one remarkable organism that dies 30% of the time in childbirth, devotes over 30% of its natural lifespan to the rearing of a single youngling, has few natural defenses or abilities, and yet has a disproportionately large brain and rather well-developed forepaws that enable it to become the dominant species on the planet.